TPS failures - better designs?

[Peter Gargano]

Sorry, I should have explained better:

Hall Effect devices are commonly used in digital (ie. ON/OFF)
mode, but they are inherently analogue devices. Rarther than 
me trying to explain how they work, try this .PDF doc (413k)

   http://www.allegromicro.com/techpub2/an/an27701.pdf

This also gives some applications of Hall devices in both 
analogue and digital modes.

Anyway, my idea is simply to use the (scaled) output of a
Hall Effect device to generate the (C) output produced by
a typical TPS. It would need +5V (B) and GND (A) from the
standard TPS plug. The magnet would make it all work, and
this is where the trickiest part would be. When the magnet
rotates (ie. when the throttle plate moves) the Hall device
will change its output voltage - this is the C output.

The whole setup is not much more than a UGN3503 (or other 
readily available analogue Hall device) feeding into an
LM124 (hi temp version of LM324) op-amp, feeding back to
the C output to the ECU.

The magnet is connected to the TPS's shaft, but otherwise,
not connected to any mechanical parts that wear out - no 
flat spots to develop, etc.

So, you're telling me no-one makes one of these?

Hmmm, damn this "prior art", and "disclosure" patent rubbish...

PG.

David Cooley wrote:
> 
> I don't see how a hall effect device could be used as a TPS.  It senses the
> presence or absence of a magnetic field...  If it was to count pulses as
> the throttle shaft was rotated to determine position, that may work, until
> someone started the vehicle with their foot on the accelerator so it
> thought it was at zero when it was at 50%...
>
-- 
Peter Gargano